5. How a parallel beam is affected by different lenses A parallel beam will converge and be focussed at the focal point: F. A parallel beam will diverge. A virtual focal point, F, can be found by projecting the rays backward. principal axis F principal axis F
6.
7.
8.
9.
10. A simple camera the film Rays from the top of the object will be focussed at the bottom of the film (and vice versa) The brightness of the image is controlled by the stop , which can be opened to make the aperture larger and let in more light. The sharpness of the image is controlled by the shutter speed. Taking pictures of moving objects require short exposures. the outer case The lens will focus the rays from the object on the film.
![WAVES : Optics (t riple science) ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]](https://image.slidesharecdn.com/lenses-110413102342-phpapp01/85/lenses-1-320.jpg)
![Reviewing refraction ,[object Object],[object Object],[object Object],[object Object]](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)